Sbl2: Hiv/aids, Shnyra

Front 1

the HIV responsible for causing AIDS in much of West Africa

the HIV responsible for AIDS throuhout the rest of the world

Back 1

HIV-2

HIV-1

Front 2

enzymes in the HIV virus that are responsible for the insertion of HIV DNA into host DNA

Back 2

reverse transcriptase and integrase

Front 3

structure of the genetic material carried in the HIV virus

Back 3

2 strands of ssRNA(+)

Front 4

blood protein that is an indicator of HIV progression

Back 4

p24 capsid protein

Front 5

matrix protein that forms the inner surface of the viral membrane

Back 5

p17 matrix protein

Front 6

outer membrane receptor molecules of the HIV virus that are involved in adsorption and penetration

Back 6

gp120 and gp41

Front 7

HIV replication is promoted by ____

HIV replication is suppressed by ____

Back 7

pro-inflammatory cytokines that activate NF-kB

CTL, chemokines, neutralizing Abs, anti-inflammatory cytokines

Front 8

half life of activated T cells that are infected by HIV

Back 8

about 1 day

Front 9

half life of macrophages and dendritic cells that are infected by HIV

Why is this important

Back 9

months/years

HIV evolved adaptations that allow replication in non-dividing macrophages...these cells serve as the the viral reservoirs

Front 10

cells that assist the HIV virus in persistent infection for months to years

Back 10

central memory T cells (long half life)

Front 11

the major hallmark of AIDS

Back 11

destruction of CD4+ T cells

Front 12

two possible ways that CD4 T cells are affected by AIDS

Back 12

directly kill
indirectly impair

Front 13

receptor for HIV on CD4+ cells

co-receptors that allow for infection of macrophages and dendritic cells

Back 13

CD4

CCR5 and CXCR4

Front 14

infection of CD4-negative macrophages occurs through the ___

Back 14

CCR5 coreceptor

Front 15

protein on dendritic cells that mediates the capture of HIV

Back 15

DC-SIGN protein

Front 16

stages of the HIV life cycle

Back 16

virus binding to host cell (gp120 and gp41)
penetration and uncoating
replication and transcription (RT then integrase)
snythesis/assembly of nucleocapsid (self assembly)
virion release

Front 17

a 32-base pair deletion in what gene renders resistance to HIV infection in homozygotes and slower progression in heterozygotes

associated w/ an inefficient entry of macrophages

Back 17

CCR-5 gene

Front 18

detection assays for HIV


Which is useful in monitoring the affect of anti-viral therapy ?

Back 18

reverse transcriptase activity (detects virus in culture)
immunofluorescence (detects antibodies)
ELISA (antibodies)
western blot (antibodies)
PCR (RNA levels)

PCR - useful in monitoring anti-viral therapy

Front 19

what determines the rate of CD4 depletion in HIV infection

Back 19

plasma "set point" for HIV RNA

Front 20

CD4/CD8 ratio in infected individuals

Back 20

less than one

normal ratio is 2:1

Front 21

cells that control HIV viremia in the acute infections (2-4 weeks)

they persist until late in infection and may cause continuing destruction of CD4 cells during the latent phase of the infection

Back 21

CD8+ cytotoxic T lymphocytes

Front 22

natural history of an HIV infection

Back 22

acute/primary phase (months)
latent phase (3-10 years)
immune collapse characterized by AIDS

Front 23

3 most common symptoms of acute HIV infection

Back 23

fever
fatigue
rash

Front 24

four stages of the progression from acute infection to AIDS

Back 24

Stage I: asymptomatic
Stage II: mucocutaneous manifestations
Stage III: chronic diarrhea, severe bacterial infections, TB
Stage IV: toxoplasmosis of brain, candidiasis of lungs, Kaposi's sarcoma

Front 25

immunosuppression in HIV infection is caused by ___

Back 25

depletion of CD4+ lymphocytes and the absence of memory cells

Front 26

auto-antibodies detected in HIV infection

Back 26

lymphocytes
platelets
neutrophils
RBCs
nerves (myelin)
ANA
thyroglobulin

Front 27

One of the ways HIV virus can survive anti-retroviral therapy is due to its ability to infect ________ and _______ cells

Back 27

macrophages and DC cells.

CD4+ T cells is also a viral reservoir

Front 28

What change to a marcrophage can render a person resistant to HIV infection

Back 28

Polymorphism of CCR5 (delta32-CCR5)

Front 29

How do Dendritic cells (DC) promote the replication of HIV virus

Back 29

1. They are suceptible to direct infection

2. Can pass the virion onto CD4+ cells

Front 30

Host immune response to HIV virus

Back 30

Abs are made to neutralize HIV virus but it can't handle the infection due variety of antigens on viral envelope...can result in AUTO-ANTIBODIES BEING MADE

Front 31

What other mutations besides delta 32 CCR5 render resistance to HIV

Back 31

mutations in genes encoding stromal cell derived factor-1 (SDF), its a ligand for CXCR4

Mutations in HLA - B27 and DR6 render resistnace

Front 32

How does HIV get so much genetic diversity

Back 32

Inaccurate enzymatic machinery reults in mutant virions

Front 33

VIRAL REPLICATION IN THE GI during Acute and chronic infection of HIV

Note: the GI is constantly stimulating an immune response to foods, bugs...

Back 33

Acute - Activated CD+ Tcells express CCR5 and are rapidly eliminated from the lamina propria by high HIV replication this may be why we see high serum titers of HIV in acute phase...as these CD4+T-cells are destroyed the lower levels of levels result in lower levels of HIV viurs in effector sites

Front 34

TH1 and TH2 response during HIV infection, what are the implications of this

Back 34

TH1 response during acute infection but shifts to Th2 w/ disease progression...results in impaired cell-mediated response (CTLs)